PEEK spacers are commonly used in spine surgery, particularly fusion surgery. Often bone graft or other fill material is used with a spacer to help promote bony fusion. It is desirable that the fill material contacts the vertebral endplates while the spacer provides structural support. In an attempt to minimize the size of spacers, traditional PEEK spacers lack adequate cavities for fill material insertion. As such, fill material is often packed around the spacer, rather than in the spacer. Uncontained fill material does pose a risk of migrating to surrounding anatomy which can lead to patient injury.
It is desirable to have a spacer small enough to be inserted via a minimally invasive or even percutaneous approach, while allowing for greater fill material containment and fill material contact with the vertebral endplates. There is a need for a PEEK spacer that is small enough to fit through an MIS or percutaneous approach, yet able to expand upon insertion to fully support and/or stabilize the intervertebral space while containing fill material therewithin.